Electric furnace structure



July 14, 1942.-

' Fig.1.-

Filed March 1, 1941 :s Sheets-Sheet 1 INVENTOR Rank 14 Brooke July 14,1942. F. w. BROOKE ELECTRIC FURNACE STRUCTURE :5 Sheets-Shet 2 FiledMarch 1, 1941 V INVENTOR Frank Brno/Fe July 14, 1942. F. w. BROOKEELECTRIQ FURNACE STRUCTURE Filod lurch 1. 1941 s Sheets-Sheet a INVENTORflank WBma/f'e Patented July 14, 1.942

ELECTRIC FURNACE STRUCTURE Frank W. Brooke, Pittsburgh, Pa., assig'norto Swindell-Dressler Corporation, Pittsburgh, Pa., a corporation ofPennsylvania I Application March 1, 1941, Serial No. 381,277

13 Claims.

This invention relates to electric furnace structure and has to do withcertain improvements in electric furnaces whereby furnace operation isimproved and furnace life lengthened. The invention has to do primarilywith the means upon which the electrodes are mounted and through whichoperative movements are imparted to the electrodes.

Electric furnaces create intense heat which adversely affects thefurnace parts. Among the parts which are readily adversely affected arevthe means for imparting operative movements to the electrodes,-that is,for feeding the electrodes toward and from the charge, in response tothe control mechanism customarily provided. Such means ordinarilycomprises a movable electrode mounting, a winch and cable connectedbetween the winch andthe electrode mounting for moving the mounting. Thewinch is subject to rapid deterioration and various proposals haveheretofore been made for protecting it from the furnace heat. Likewise,when an electrode arm which is movable upon a stationary mast isemployed the connection between the arm and mast which is in the zone ofgreatest heat is readily subject to the adverse effects of the furnaceheat.

I have devised an electric furnace structure in which virtually allmovable parts are disposed laterally of the furnace body rather thansuperimproved thereupon and are otherwise protected to the maximumextent from the furnace heat; It is to be borne in mind that when thefurnace roof is open a very high heat emanates from the top of thefurnace body. This heat is detrimental to any movable parts which may bedisposed above the furnace. I preferably mount the electrode operatingwinches laterally of the furnace and below the level of the top of thefurnace body. I preferably provide a mounting disposed laterally of thefurnace and mount therein vertically movable masts carrying fixedelectrode arms so that the points of movable connection between themasts and the supporting mechanism are mainly or wholly below the levelof the top of the furnace body and disposed laterally of the furnace. Ialso preferably provide for protecting the winches by disposing othermeans serving a dual operating and protective function between thewinches and the furnace body. When the roof is mounted upon a pivot atthe side of the furnace for laterally swinging movement ing mast ispreferably interposed between the winch and the furnace body. Thus suchwinch is afforded a maximum of protection from the furnace heat both byreason of its peculiar position and by reason of the interposition between it and the body of other. devices which are in the direct path ofthe furnace heat. Also I prefer to provide connections between thewinches and the vertically movable masts which are disposed entirelybelow the level of the top'of the furnace body. My structure resultsin-a furnace having extremely long life and which is exceptionallyreliable in operation.

Heretofore in electric furnaces of the type having a roof laterallyswingable to open the furnace at the top for charging the'roof has beensupported mainly from an edge portion thereof upon a casting mounted onthe pivot about which the roof swings. Thus the roof or the portionthereof which closes the furnace is mounted somewhat in cantileverfashion and the roof refractories and the steel ring which retains themhave consequently been subjected to severe stresses which haveconsiderably shortened the useful life of the roof. I provide for freelysupporting the furnace closing portion of the roof in such a way that itis free independently to expand and contract due to temperature changesand also to'adjust itself accurately to the body of the furnace whenapplied thereto to close the furnace. Preferably the furnace closingportion of the roof is supported from the supporting or carrying por-vtion by means'disposed about a vertical line passing through the centerof gravity of the furnace closing portion. In a preferred structure thefurnace closing portion of the roof is freely suspended at a number ofpoints spaced around its periphery so that the stresses to which it. issub the pivot is preferably interposed between the body of the furnaceand one of the winches which at the same time is disposed below thelevel of the top of the body. Also the correspondjected are greatlyreduced and its useful life is correspondingly lengthened. Expansion andcontraction of the roof without restraint under the the old roof andapplication of the new has been.

accomplished only with considerable difliculty because of the manner inwhich the roof has been held by the supporting casting. In my improvedconstruction this change is accomplished readily and with great savingof time and labor. The furnace closing portion of the roof is simplyfreed from the supporting beams by disengaging the links which suspendit. By means of the mechanism which ordinarily raises and swings asidethe furnace closing portionof the roof for charging purposes thesupporting beams and all superstructure are raised and swung aside,leaving the furnace closing portion of the roof in place upon thefurnace body from which it can be readily removed by a crane. By areversal of this process the new roof is readily placed upon the furnaceand connected to the supporting beams.

Other details, objects and advantages of the invention will becomeapparent as the following description of a present preferred embodimentthereof proceeds.

in the accompanying drawings I have shown a present preferred embodimentof the invention, in which Figure l. is an elevational view withportions cut away of an electric furnace structure;

Figure 2 is an elevational view with portions cut away and to enlargedscale of the structure shown in Figure 1, but viewing the furnace fromthe right-hand side of Figure 1;

Figure 3 is a view partly in plan and partly in horizontal cross sectionthrough the furnace structure shown in Figures 1 and 2 and with portionsomitted to enable a clearer showing of other portions; and

Figure 4 is a vertical cross-sectional detail view to enlarged scaleshowing one of the groups of positioning and guiding rollersfor'positioning and guiding a mast and the support for such group ofrollers.

Referring now more particularly to the drawings, there is shown anelectric furnace comprising a body 2 and a roof 3. The furnace body maybe of more or less standard construction, being tiltable upon tracks 4by any suitable mechanism, such, for example, as hydraulic cylinders 5.The usual liftable side door 6 is provided, which door may be operatedin any convenient manner.

Fastened to the side of the body 2 is a vertical cylinder 1 within whichis disposed a roof supporting piston 8. Suitable fluid connections areprovided, as well known in the art, for raising and lowering the piston8 in the cylinder 1. Also a transverse cylinder 9 is provided withinwhich is disposed a piston operated by known means for turning thepiston 8 in the cylinder 1. Consequently by suitable operation of thecontrol mechanism the piston 8 may be raised in the cylinder 1 and alsoturned about its axis. This structure is already known in the art.

Carried upon the upper end of the piston 8 is a roof support or carryingroof portion l0. Connected with the roof support and extending laterallytherefrom over top the furnace are lower winch shown in Figure 3.

It consists of an upper group of rollers carried in a support Ma and alower group of rollers carried in a support Mb. Each mast 95 hasconnected to it at its top, preferably permanently, an electrode arm itwhich extends over the furnace and carries at its extremity an electrodeholder ill in which is held a generally vertically extending electrodeit. Each of the three electrodes passes downwardly through a suitableopening in the roof 33 as well known in the art. Current to eachelectrode is supplied through a conductor it.

Mounted on the frame it are three winches 20, one corresponding to eachmast it. As will be noted from Figure 3, each mast is interposed betweenthe corresponding winch and the furnace body when the roof is closed,which is the normal position of the roof. Also the cylinder l isinterposed between the furnace body and the Moreover, the winches aredisposed so that they are at all times entirely below the level of thetop of the furnace body in addition to being spaced quite a substantialdistance away from the furnace body. They are thus afforded the maximumof protection from the furnace heat. Each winch is driven by an electricmotor 2i mounted atop the winch. The winch structure per se may bestandard.

Each mast it: has a sheave 22 pivoted thereto at 23 at its bottom. Eachwinch it has a cable 2 3 wound on the winch drum and extending therefromgenerally downwardly and about the bottom of the sheave 22 of thecorresponding mast l and thence extending generally upward and beingdead-ended to an eye 25 held in the frame 83.

Each mast i5 is supported solely by the corresponding cable 24,. It ismerely guided by the guide rollers M which maintain it in verticalposition and facilitate its movement. Upon operation of a winch to windup on its drum the cable 2 3 connected therewith the corresponding masti5 is raised'which results in corresponding raising of the electrode itcarried by the arm it fast to that particular mast. Conversely, when awinch pays out its cable 2t this allows the corresponding mast E5 tomove downwardly due to gravity and the electrode carried thereby movestherewith. There are no moving .parts other than the unit comprising therelatively fixed members [5 to l9, inclusive, above the body of thefurnace.' The winches and their cables beams II, from which the roofproper or furnace and the connections with the masts are all far belowthe top of the furnace body. The guides for the masts are disposedlaterally of the furnace body and are out of the zone of greatest heat.The winches are also protected from the furnace heat by being removed asubstantial distance from the furnace and also by having the masts I5and, in the case of one winch, the cylinder 1 interposed between themand the furnace body. The furnace is exceptionally sturdy and foolproofand the repairs and adjustments ordinarily. necessary to moving partsare virtually eliminated.

While I have shown and described a present preferred embodiment of theinvention it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied within the scopeof the following claims.

Iclaim:

1. Electric furnace structure comprising a furnace body, a roof for thebody, means for swingcarried by the roof for imparting operativemovements to the electrode, said means including a motive unit disposedbelow the level of the top .of the body when the roof is in its highestposition.

3. Electric furnace structure comprising a furnace body, a roof for thebody, means for swinging the roof laterally in opening and closingmovements, an electrode and means for imparting operative movements tothe electrode, said means including a mast carried by the roof andgenerally vertically movable relatively thereto, an electrode holdercarried by the mast and means for raising and lowering the mastrelatively to the roof.

4. Electric furnace structure comprising a furnace body, a roof for thebody, means for swing ing the roof laterally in opening and closingmovements, an electrode and means for imparting operative movements tothe electrode, said means including a mast generally vertically movableto impart such movements to the electrode, an electrode holder carriedby the mast, a motive unit and connections between the motive unit andmast for generally vertically moving the mast, said connections beingdisposed below the level of the top of the body.

5. Electric furnace structure comprising a furnace body, an openableroof for the body, an electrode and means for imparting operativemovements to the electrode, said means including a mast carried by theroof and generally vertically movable relatively thereto, an electrodeholder carried by the mast and means iiieluding a motive unit carried bythe roof below the level of the top of the body for raising and v nacebody, a roof for the body, an electrode,

means for imparting operative movements to the electrode, said meansincluding a motive unit carried by the roof and disposed below the levelof the top of the body, and means interposed between the body and motiveunit shielding the motive unit from the heat of the body.

8. Electric furnace structure comprising a furnace body, a roof for thebody, means for swinging the roof laterally in opening and closingmovements, an electrode, a vertically movable mast, an electrode holdercarried by the mast for holding the electrode, a motive unit disposedbelow the level of the top of the furnace body and connections betweenthe motive unit and mast whereby the former operates the latter forimparting operative movements to the electrode, the mast being normallyinterposed between th furnace body and the motive unit.

9. Electric furnace structure comprising a furnace body, a roof, a pivotconnected with the body upon which the roof is mounted and aboutthe'axis' of which the roof is swingable relatively to the body inopening and closing movements,

an electrode and means for imparting operative movements to theelectrode, said means including a mast carried by the roof and generallyvertically movable relatively thereto and a motive unit operativelyconnected with the mast for raising and lowering the same, the pivotbeing normally interposed between the furnace body and the motive unit.

10. Electric furnace structure comprising a furnace body, a roof, apivot connected with the body upon which the roof is mounted and aboutthe axis of which the roof is swingable relatively to the body inopening and closing movements, an electrode and means for impartingoperative movementsto the electrode, said means including a mast carriedby the roof and generally vertically movable relatively thereto and amotive unit operatively connected with the mast for raising and loweringthe same, the pivot and mast being normally interposed between thefurnace body and the motive unit.

11. Electric furnace structure comprising a furnace body, a roof forthebody, the roof having a generally downwardly projecting portiondisposed laterally of the body, an electrode, a vertically movable mastpassing through and guided by said portion, an electrode holder carriedby the mast for holding the electrode, a motive unit carried by saidportion and connections between the motive unit and the mast for raisingand lowering the mast. 7

12. Electric furnace structure comprising a furnace body, a roof for thebody, the roof having a generally downwardly projecting portion disposedlaterally of the body, an electrode, a vertically movable mast passingthrough and guided by said portion, an electrode holder car- 'ried bythe mast for holding the electrode, a

winch carried by said portion and a cable connectedwith the winch andextending generally downwardly therefrom and connected with the mast atthe lower portion thereof for raising and lowering the mast.

13. Electric furnace structure comprising a furnace body, a roof, apivot connected with the body, the roof having a generally downwardlyprojecting portion the lower part of which is disposed laterally of thebody, the roof beingmounted on the pivot through a part of said portionwhereby the roof is swingable relatively to the body in opening andclosing movements, an electrode, a vertically movable mast passingthrough and guided by said portion, an electrode holder carried by themast for holding the electrode, a winch carried by said portion belowthe level of the top of the body and a cable connected with the winchand extending generally downwardly therefrom and connected with the mastat the lower portion thereof for raising and lowering the mast, thepivot being normally interposed between the furnace body and the winch.

- FRANK W. BROOKE.

